Shape and Space 2

2 marks · Easy

Look at the circle below. O is the centre, and AB is a chord. OM is perpendicular to AB. AB = 10 cm. OM = 4 cm.

Circle with centre O, chord AB, midpoint M, and perpendicular OM.

(a)

Write down the length of AM.

[1 mark]

(b)

Calculate the radius of the circle to 1 decimal place.

[1 mark]

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

Show answer

(a) 5 cm

(b) 6.4 cm

Show mark scheme and worked solution

Marking points

B1 (a) · 1 mark · States that AM = 5 cm, given OM bisects AB.

M1A1 (b) · 1 mark · Uses Pythagoras' theorem to find OA (radius), OA = cm (1 dp).

Worked solution

a) AM is half of AB: cm